Contrary to a hinged frame, such as that, for example, of a door or a window, which swings open about hinges, a sliding frame is a type of frame which commonly opens by sliding horizontally along, for example, a wall or into a pocket in a wall. Sliding frames are commonly either mounted on or suspended from a track employing a sliding frame gear mechanism.
Sliding gear mechanisms are commonly made of metal materials such as aluminum, plastic polymers or a combination of plastic polymers, such as Teflon®, that have a lower friction co-efficient than high density polyethylene and commonly include two basic types: the top hung mechanism, in which the frame is hung from a track by two trolley hangers or a bottom rolling mechanism. The top hung type sliding gear mechanism requires guides at the bottom of the frame to prevent lateral pendulous swinging of the frame. Such guides may include, for example, a stationary guide on which rides a groove cut into and along the bottom of the sliding frame, a groove in the threshold or sill and several horizontally rotatable wheels attached to the bottom of the frame and ride along the upright walls of the groove or similar mechanisms.
A bottom rolling apparatus consists of two or more rollers at the bottom of the frame which run on a track and a guide at the top which runs, for example, in a guide channel cut into the frame casing or header.
The above described sliding gear mechanisms have several drawbacks such as, for example, friction between the wheels and the track which increases the amount of force required to slide the frame back and forth. Another drawback is the sensitivity of these mechanisms to dust or debris which may be trapped either in the wheel axes or in the track impeding the wheels, preventing them from running smoothly and requiring periodical maintenance such as lubrication, cleaning and occasionally replacement of worn wheels.
Additionally, the above described sliding gear mechanisms are also affected by manufacturing imperfections, for example, imperfection of the rail such as a slightly curved track or minor protrusions or grooves along the riding track of the rail which may prevent the wheeled gear mechanism from running smoothly.
Several attempts have been made to develop reduced friction frame sliding gear mechanisms employing materials such as Teflon®, semi-frictionless frame sliding gear mechanisms employing magnets and wheels or contactless mechanism employing magnets alone.
Contactless, and frictionless magnet-based sliding gear mechanisms rely on the repelling forces which develop between two adjacent magnets, one located in the base of the frame and the second in the threshold or sill and having the same magnetic field orientation to overcome gravity and allow suspension of the frame in mid-air. The advantage of such mechanisms primarily lies in them being maintenance free having no moving parts such as wheels.
As in the mounted or suspended sliding frame gear mechanisms, contactless, magnet-based sliding gear mechanisms also require lateral stabilization of the frame to prevent it from swinging or deviating sideways. Attempts have been made to meet this requirement. Such attempts involve complex series of magnets vertically placed on the lateral aspects of the frame bottom or top aspects and along the vertical walls of a groove in the threshold or sill or in the header. Other attempts involve grooves and guides similar to those described above and other similar mechanisms.
The present apparatus and method present a simple and maintenance-free contactless and frictionless frame sliding gear mechanism, which is designed to continuously maintain an equilibrium between forces acting on the sliding frame at any point along the path of translation of the frame. This not only provides a solution for preventing the frame from swinging or deviating sideways, both in a stationary position as well as during translation, but also ensures smooth, unhindered translation of the frame, regardless of its spatial orientation.